A complete True and Relative Plotting marine radar system. The transistorised plotting unit operates from the power unit and provides a north-up relative motion record of all measurements of range & brearing made from either true or relative motion information displayed on the P.P.I.
The main components are:
Automatic Relative Plotter: Type 467Ca. Class B. Provides a relative motion north stabilised plot 18'' in diameter. Supplied with pedestrial.
Performance Monitor: Cavity Unit Type 4794A, Class B. This Unit checks the efficiency of the entire radar set and indicates faults in transmitter & circiuts.
Display Unit: Type 4803CA. Class B. Together with Display Console Unit Type 4822AY. ClassB. Contains catode ray tube and all circuits associated with the production of rotating trace, and arrangemens for azimuth stablisation of the display. Picture is presented on a 10.5" effective diameter CRT.
Viewer Unit. (Hood): Type 4805B. Class B.
Transciever Unit: Type 4810 Class B. Contains the transmitter, the reciever and their suppliers. An anti-condensation heater is provided.
Control Unit: Type 4423MY. Mark II.ClassB. This unit automatically regulates the alternator output voltage to the electronic units.
Monitor Generator: Type 4422MQ. 1.5 h.p. 230/240v.
Scanner Unit: Type 4831. 9ft. Comprises aerial geabox, turning motor and bearing transmitter. The aerial is an end-fed slotted waveguide array.

Decca Manuals for Radar Type 629 and for Automatic Relative Plotter Type 50.